Methods and systems for characterizing fluids from a patient

Abstract

Methods for characterizing fluids from a patient. A time series of images of a conduit are received, and a conduit image region in the images is identified. The conduit image region may include a shallow section and/or a deep section. The shallow section includes a dimension of the conduit along an optical axis of the camera such that opacity of the fluids from redness associated with red blood cells or hemoglobin is limited to permit pixel color visualization in the images. The deep section includes a dimension is along the optical axis such that the redness provides a minimum opacity to permit the pixel color visualization. A concentration of a blood component of the fluids is determined based on the pixel color visualization. A volume of blood passing through the conduit is estimated based on the estimated concentration of the blood component and an estimated volumetric flow rate.

The invention claimed is: 
     
       1. A computer-implemented method for estimating a volume of blood within fluids being drawn through a conduit with a system including a camera, one or more processors, and a display, the method comprising:
 receiving a time series of images of a conduit image region of the conduit, wherein the conduit image region includes a shallow section in which a dimension of the conduit along an optical axis of the camera is such that opacity of the fluids from redness associated with red blood cells or hemoglobin is limited to permit pixel color visualization in the time series of images; 
 estimating a concentration of a blood component of the fluids based on the pixel color visualization; 
 estimating a volumetric flow rate of the fluids; 
 estimating the volume of blood passing through the conduit based on the estimated concentration of the blood component and the estimated volumetric flow rate; and 
 displaying, on a display, the estimated volume of blood. 
 
     
     
       2. The method of  claim 1 , further comprising:
 classifying a flow type of the fluids passing through the conduit; and 
 estimating the volumetric flow rate of the fluids in the conduit based on the classified flow type. 
 
     
     
       3. The method of  claim 1 , further comprising:
 receiving conduit-related information including the dimension of the conduit; and 
 estimating the volumetric flow rate of the fluids in the conduit based on the conduit-related information. 
 
     
     
       4. The method of  claim 3 , wherein the conduit-related information is associated with an optical fiducial, the method further comprising:
 imaging the optical fiducial with the camera; and 
 accessing a database to obtain the conduit-related information. 
 
     
     
       5. The method of  claim 1 , wherein the shallow section is flattened with an internal volume that is substantially uniform along a length of the shallow section. 
     
     
       6. The method of  claim 5 , wherein a width-to-depth ratio of the flattened shallow section is approximately 20:1. 
     
     
       7. The method of  claim 1 , wherein the dimension is within the range of 0.5 to 5 millimeters. 
     
     
       8. The method of  claim 1 , wherein the conduit image region further includes a deep section in which a dimension of the conduit along the optical axis of the camera is such that red blood cells or hemoglobin within the flow of fluids provides a minimum opacity of the blood being imaged by the camera. 
     
     
       9. The method of  claim 8 , wherein the deep section has a depth along the optical axis of the camera within the range of 5 to 20 millimeters. 
     
     
       10. The method of  claim 1 , wherein the conduit comprises a deep section near an outlet of the conduit and tapers to the shallow section near an inlet of the conduit. 
     
     
       11. The method of  claim 10 , wherein the conduit tapers in multiple planes. 
     
     
       12. The method of  claim 1 , wherein the conduit comprises an entrapment region of expanded volume or constricted areas so as to reduce speed of the fluid, and wherein the method further comprises imaging the entrapment region. 
     
     
       13. The method of  claim 1 , wherein the conduit includes internal channels providing multiple orifices of smaller cross section. 
     
     
       14. A computer-implemented method for estimating a volume of blood within fluids being drawn through a conduit with a system including a camera, one or more processors, and a display, the method comprising:
 receiving a time series of images of a conduit image region of the conduit, wherein the conduit image region includes a deep section in which a dimension of the conduit along an optical axis of the camera is such that redness associated with red blood cells or hemoglobin within the fluids provides a minimum opacity to permit pixel color visualization in the time series of images; 
 estimating a concentration of a blood component of the fluids based on the pixel color visualization; 
 estimating a volumetric flow rate of the fluids; 
 estimating the volume of blood passing through the conduit based on the estimated concentration of the blood component and the estimated volumetric flow rate; and 
 displaying, on a display, the estimated volume of blood. 
 
     
     
       15. The method of  claim 14 , further comprising:
 receiving conduit-related information including the dimension of the conduit; and 
 estimating the volumetric flow rate of the fluids in the conduit based on the conduit-related information. 
 
     
     
       16. The method of  claim 15 , wherein the conduit-related information is associated with an optical fiducial, the method further comprising:
 imaging the optical fiducial with the camera; and 
 accessing a database to obtain the conduit-related information. 
 
     
     
       17. The method of  claim 14 , wherein the dimension is within the range of 5 to 20 millimeters. 
     
     
       18. A computer-implemented method for estimating a volume of blood within fluids being drawn through a conduit with a system including a camera, one or more processors, and a display, the method comprising:
 imaging an optical fiducial with the camera; 
 accessing a database to obtain conduit-related information of the conduit based on a code of the optical fiducial, wherein the conduit-related information includes at least one dimension associated with a conduit image region of the conduit; 
 receiving a time series of images of a conduit image region of the conduit, 
 estimating a concentration of a blood component of the fluids based on pixel color visualization in the time series of images; 
 estimating a volumetric flow rate of the fluids; 
 estimating the volume of blood passing through the conduit based on the estimated concentration of the blood component and the estimated volumetric flow rate; and 
 displaying, on the display, the estimated volume of blood. 
 
     
     
       19. The method of  claim 18 , wherein the conduit image region includes a shallow section in which the at least one dimension is along an optical axis of the camera is such that opacity of the fluids from redness associated with red blood cells or hemoglobin is limited to permit the pixel color visualization in the time series of images. 
     
     
       20. The method of  claim 18 , wherein the conduit image region includes a deep section in which the at least one dimension is along an optical axis of the camera is such that red blood cells or hemoglobin within the flow of fluids provides a minimum opacity to permit pixel color visualization in the time series of images.